Dual self-lapping control valve



United States Patent Office 3,328,692 Patented June 27, 1967 3,328,092 DUAL SELF-LAPPIN G CONTROL VALVE Richard C. Bueler, Glendale, Mo., assignor to Wagner Electric Corporation, St. Louis, Mo., a corporation of Delaware Filed Dec. 22, 1965, Ser. No. 515,692 14 Claims. (Cl. 303-52) This invention relates to cont-r01 valves and in particular to control valves of the ratio application type.

An object of the present invention is to provide a control valve having applied force responsive means therein controlling the application of fluid pressure from a source thereof to a fluid pressure responsive motor and including means responsive to the applied fluid pressure for effecting the application thereof to another fluid pressure responsive motor in a predetermined ratio with that applied to said first named motor.

Another object of the present invention is to provide a control valve having applied force responsive means and fluid pressure responsive means therein for controlling the application of fluid pressure from a source thereof to a pair of pressure fluid responsive motors and means for selectively predetermining the ratio between the magnitudes of the applied fluid pressures.

Another object of the present invention is to provide a control valve which is selectively operable to effect non-ratio and ratio fluid pressure applications between a fluid pressure source and a pair of fluid pressure responsive motors including means for overriding the ratio application to effect a non-ratio application.

And another object of the present invention is to provide a control valve which is selectively operable to effect nonratio and ratio pressure fluid communication between an inlet port and a pair of outlet ports provided therein including mechanically operable means for interconnecting said outlet ports with each other to simulate nonratio pressure fluid communication therebetween when said control valve is selectively conditioned to effect the ratio pressure fluid communication between said outlet ports.

And still another object of the present invention is to provide a control valve having selectively operable means for establishing pressure fluid communication between an inlet port and an outlet port thereof and other means responsive to the established fluid pressure at said outlet port provided in said control valve wherein the established fluid pressure is in a predetermined ratio with the applied fluid pressure at said other outlet port.

These and other objects of the present invention will become apparent hereinafter.

Briefly, the invention comprises a control valve having application means therein movable in response to an applied force to establish pressure fluid communication between a fluid pressure source and a fluid pressure responsive motor and other application means movable in response to the established fluid pressure to eflect the application thereof to another fluid pressure responsive motor wherein the established fluid pressure at said first named motor and the applied fluid pressure at said other motor are in a predetermined ratio. The invention also includes means on said one application means for selective subjection to either the atmosphere or one of the established and applied fluid pressures to effect a ratio between the applied and established fluid pressures different than the predetermined ratio. And the invention also includes mechanical means for interconnection between the first named and other application means to mechanically override the ratio function of the other application means.

In the drawing, a diagrammatic view of a fluid pressure system is shown having a control valve therein in cross-section embodying the present invention.

Referring to the drawing, a fluid pressure system 1 is shown having fluid pressure generating means, such as a compressor 2, connected with the inlet port of a control or application valve 3 by a conduit 4 with a reservoir 5 interposed therein, said reservoir and compressor forming, in combination, a source of fluid pressure. Fluid pressure responsive motors or brake chambers 6, 7 are connected by conduits 8, 9 to a pair of outlet ports provided in the control valve 3 and said motors are operatively connected with slack adjustors 10, 11 to control the energization of different axle vehicle brake assemblies (not shown). Another conduit 12 is connected between a ratio port provided in the control valve 3 and the conduit 8, and an operator controlled two-way or hand valve 13 is connected in said conduit. The two-way valve 13 is provided with connecting ports 14, 15 and an atmospheric port 16, and rotatable passage means 17 is selectively movable between said ports. While the conduit 12, as shown, is connected between the ratio port of the control valve 3 and the conduit 8, said conduit 12 can also be connected between the ratio port of said control valve and the conduit 9 if desired. To complete the description of the system 1, the passage means 17 in one position, as shown, connects the connecting ports 14, 15 in open pressure fluid communication, and upon rotation thereof in a clockwise direction (as shown by the directional arrow) to its other position, said passage means interrupts pressure fluid communication between the connecting ports 14, 15 and establishes open pressure fluid communication between the connecting and atmospheric ports 15, 16.

The control valve 3 is provided with an upper housing 18 which is connected to an upper end portion 19 of an intermediate housing or separation plate 20 by suitable means, such as a plurality of studs 21. A lower housing 22 is connected with lower end portion 23 of the intermediate housing 20 by suitable means, such as a plurality of studs 24, and a sealing ring 25 is sealably interposed between said intermediate and lower housings.

The upper housing 18 is provided with a bore or connecting passage 26 defining an annular wall 27 axially positioned between a stepped counterbore or outlet chamber 28 and another counterbore or inlet chamber 29. An inlet port 30, which receives the conduit 4, as previously mentioned, is provided in the upper housing 18 connecting with the counterbore 29, and an outlet port 31, which receives the conduit 8, as previously mentioned, is provided in said upper housing connecting with the counterbore 28.

A recess 32 is provided in the upper portion 19 of the intermediate housing 20 beneath the counterbore 29, and an exhaust port 33 and passage 34 are provided in the upper housing 18 connecting with said recess. A value guide member 35 is received in the counterbore 29 and is normally seated on the upper end 19 of the intermediate housing 20. The valve guide member 35 is provided with a bore 36 in which an inlet valve element 37 is slidable, and seals 38, 39 are carried in said valve guide member in sealing engagement with the counterbore 29 and said inlet valve element, respectively. The inlet valve element 37 is provided with an axial exhaust bore or opening 40 therethrough, and an annular resilient seal or disc 41 is provided on the upper end of said inlet valve element in circumscribing relation with said exhaust opening. A valve spring 42 is biased between the valve guide member 35, and the inlet valve element 37 normally urging the valve seal 41 into sealing engagement with .a valve seat 1% 43 which is provided on the upper housing wall 27 at the juncture of the bore 26 and counterbore 29.

An application or valve control member, such as reaction piston 44, is slidably received in the counterbore 28, and a peripheral seal 45 is carried in said reaction piston in sealing engagement with said counterbore. The reaction piston 44 is provided with a valve seat 46 thereon which is substantially coaxial with the upper housing bore 26, and said valve seat is normally maintained in spaced relation with the seal 41 of the inlet valve element 37 by a return spring 47 which is interposed between said reaction piston and the upper housing 18. A metering spring bore 4-8 is provided in the reaction piston 44, and a pre-compressed metering spring 49 is retained therein by a retainer or treadle force receiving plate 50 which is normally biased into abutting engagement with a snap ring and groove assembly 51 provided in the upper end of said metering spring bore.

The intermediate housing 20 is provided with centrally located stepped bores 52, 53 having an annular shoulder 53a therebetween, and a control or ratio port 54 which receives the conduit 12, as previously mentioned, is provided in said intermediate housing and connected with the shoulder defined between said stepped bores. The lower housing 22 is provided with a bore 55, the lower end of which is closed by a radially extending end Wall 56 integrally provided on the lower housing 22. Another outlet port 57 which receives the conduit 9, as previously mentioned, is provided in the housing end wall 56 connecting with the bore 55, and a valve seat 58 is centrally provided on the housing end wall 56 having an exhaust passage or port 59 extending coaxially therethrough to normally vent the outlet port 57 to the atmosphere,

An application or valve control member, such as a stepped metering piston 60, is slidably received in the intermediate housing stepped bore 53 and the lower housing bore 55-, and peripheral seals 61, 62 are carried in said metering piston in sealing engagement with said stepped bore and bore, respectively. Stepped bores 63, 64 are axially provided through the metering piston 60, and a valve seat 65 is defined at the juncture of said stepped bores 63, 64. A bore closure member 66 is fixedly received in the stepped bore 63 adjacent the upper end thereof having a peripheral seal 66a in sealing engagement with the piston stepped bore 63, and another inlet valve element 67 is normally urged into engagement with the valve seat 65 by a valve spring 68 biased between said valve element and said bore closure member. The valve element 67 is normally maintained in predetermined spaced relation with the exhaust valve seat 58 by .a return spring 69 interposed between the metering piston 60 and the lower housing end wall 56, and a cross-passage 69a is provided in said metering piston between the stepped bore 63 thereof and an application chamber 70 defined in said lower housing bore between the upper end of said metering piston and said intermediate housing. An outlet chamber 71 is defined in the lower housing bore 55 between the lower end of the metering piston 60 and the lower housing end wall 56 in pressure fluid communication with the outlet port 57. The application chamber 70 is connected with the upper housing counterbore 28 by passage 72 which is provided in the upper and intermediate housings 18, 20, and a control chamber 73 is defined in the intermediate housing stepped bore 53 between the shoulder 53a and the metering piston 60 therein in pressure fluid communication with the ratio port 54. It should be noted that the metering piston 60 is provided with an area A in the application chamber 70 which is opposed by another area A on said metering piston in the outlet chamber 71. A control area A is also provided on the metering piston 60 in the control chamber 73, and the area A is additive to the area A and substantially equal to the difference between areas A and A To complete the description of the control valve 3, a link 74 or lost motion connection is slidably received in the intermediate housing stepped bore 52 having a peripheral seal 75' thereon in sealing engagement with said intermediate housing stepped bore. The lower end of the link 74 extends into the control chamber 73 into driving engagement with the closure member 66 of the metering piston 60, and the upper end of said link extends coaxially through the exhaust opening of the inlet valve element 37 for driven engagement with the valve seat 46 of the reaction piston 44.

In order to effect a non-ratio braking application with the rotatable passage means 17 of the two-way valve 13 connecting the ratio port 54 in pressure fluid communication with the conduit 8 through the conduit 12, as previously described, a manual force is applied by the operator on the force receiving plate of the reaction piston 44 to move said reaction piston and the valve seat 46 thereof downwardly to sealably engage said valve seat with the inlet valve element 37 closing the exhaust passage 40 thereof and isolating the outlet chamber 28 from the atmosphere. Further downward movement of the reaction piston 44 disengages the inlet valve element 37 from the upper housing valve seat 43 to establish pressure fluid communication between the inlet and outlet ports 30, 31. The pressure fluid flows from the reservoir 5 through the conduit 4, the inlet port 30, the inlet chamber 29 and the upper housing bore 26 into the outlet chamber 28 and the outlet port 31 and therefrom through the conduit 8 to actuate the brake chamber 6 and rotate the slack adjustor 10 to energize the wheel brake assembly associated therewith. At the same time, the established fluid pressure flows from the conduit 8 through the conduit 12, the two-way valve 13 and the ratio port 54 into the ratio chamber 73, and the established fluid pressure also flows from the outlet chamber 28 through the passage 72 into the application chamber 70. The established fluid pressure in the application and ratio chambers 70, 73 respectively acts on the eflective areas A A of the metering piston therein creating an application force effective to move said metering piston downwardly against the negligible force of the return spring 69 to initially engage the valve element 67 with the housing valve seat 53 closing the exhaust passage 59 and isolating the outlet chamber 71 from the atmosphere. Further downward movement of the metering piston 66 relative to the valve element 67 disengages the metering piston valve seat from said valve element to eflect a metered application of the established fluid pressure from the outlet port 31 to the outlet port 57, and in this manner the applied fluid pressure at the outlet port 57 acts on the area A of said metering piston in the outlet chamber 71 to create another reaction force in opposition to the application force. The established fluid pressure is applied from the application chamber through the cross-passage 69a in the relay piston 60 and the stepped bores 63, 64 to the outlet chamber 71 and therefrom through the outlet port 57 and conduit 9 to actuate the brake chamber 7 and rotate the slack adjustor '11 thereby energizing the wheel brake assembly associated therewith. From the foregoing, it is apparent that the established fluid pressure at the outlet port 31 is controllably metered to create an applied fluid pressure at the outlet port 57, said applied and established fluid pressures being substantially equal, i.e., in substantially a 1:1 ratio.

When the reaction force created by the established fluid pressure in the outlet chamber 28 acting on the eflective area of the reaction piston 44 equals the manually applied force thereon, said reaction piston is moved upwardly against the metering spring 49 wherein the inlet valve element 37 is positioned in lapped engagement with the upper housing valve seat 43 and the reaction piston valve seat 46 is positioned in lapped engagement with said inlet valve element. The reaction force acting through the metering spring against the manually applied force on the plate 50 affords the operator a direct and accurate feel as to the extent of the braking effort or application. Similarly, when the reaction force created by the applied fluid pressure in the outlet chamber 71 acting on the effective area A of the metering piston 60 equals the application force of the established fluid pressure in the application and ratio chambers 70, 73 acting on the effective areas A A of said metering piston, said metering piston is moved upwardly wherein the metering piston valve seat 65 is positioned in lapped engagement with the valve element 67 and said valve element is positioned in lapped engagement with the housing valve seat 58. If greater braking effort is desired, the manually applied force is increased which results in an increased application force, and the component parts of the control valve 3 function in the same manner as previously described to again move said component parts to their lapped positions.

When the desired braking effort is obtained, the manually applied force is removed from the reaction piston 44, and the reaction force on said reaction piston plus the compressive force of the return spring 47 moves said reaction piston upwardly toward its original or inoperative position. Since the valve element 37 is sealably engaged with the upper housing valve seat 43, the pressure fluid communication between the inlet and outlet ports 30, 31 is interrupted, and the upward movement of the reaction piston 44 disengages the seat 46 from said inlet valve element 37 to re-establish communication between said outlet port and the atmosphere and eliminate the reaction force on said reaction piston. The wheel brake assembly associated with the outlet port 31 is de-energized upon the exhaustion of the established fluid pressure to the atmosphere from the brake chamber 6 through the conduit 8, said outlet port, the outlet chamber 28, the inlet valve exhaust passage 40, the exhaust chamber 32 of the intermediate housing Ztl and the exhaust port and passage 33, 34 of the upper housing 18. At the same time, the established fluid pressure is also exhausted from the control chamber 73 though the ratio port 54, the conduit 12, the two-way valve 13, and the conduit 8 into the outlet chamber 28 as well as from the application chamber 70 through the housing passage 72 into the outlet chamber 28 and therefrom to atmosphere, as previously described above. In this manner, the application force on the metering piston 66 is also eliminated and the reaction force on said metering piston plus the compressive force of the return spring 69 moves said metering piston upwardly toward its original or inoperative position. Since the valve element 67 is sealably engaged with the metering piston valve seat 65, communication between the outlet ports 31, 57 is interrupted, and the upward movement of the metering piston 60 disengages said valve element from the housing valve seat 58 to open the exhaust passage 59 and re-establish communication between the outlet port 57 and the atmosphere thereby eliminating the reaction force on said metering piston. The wheel brake assembly associated with the outlet port 57 is de-energized upon the exhaustion of the applied fluid pressure to the atmosphere from the brake chamber 7 through the conduit 9, the outlet port 57 and the exhaust chamber 71 to the exhaust port 59.

Since the additive effective input areas A A of the metering piston 60 in the application and ratio chambers 70, 73 are substantially equal to and opposite the effective output area A of said metering piston in the outlet chamber 71, it is apparent that the above-described braking application results in a substantially 1:1 ratio between the established fluid pressure at the outlet port 31 and the applied fluid pressure at the outlet port 57. If the operator desires to reduce the magnitude of the applied fluid pressure at the outlet port 57 to effect a ratio braking application wherein the ratio between the established fluid pressure and the applied fluid pressure at the outlet ports 31, 57, respectively, is less than 1:1, the rotatable passage 17 is rotated clockwise (in the direction of the arrow) to a position in the two-way valve 13 aligned between the connecting port 15 and exhaust 16 thereof. In this manner, communication between the outlet chamber 28 and the ratio port 54 is interrupted, and the ratio chamber 73 is vented to atmosphere through said ratio port, the conduit 12 and the connecting port, rotatable passage means and exhaust 15, 16 and 17, respectively, of the two-way valve 13. A manually applied force on the reaction piston 44 by the operator actuates the valve element 37 to establish fluid pressure at the outlet port 37, as previously described. Since the two-way valve 13 is positioned to obviate flow to the control chamber 73, the esablished fluid pressure is passed only through the housing passage 72 into the application chamber 70 acting on only the efiective area A of the metering piston 60 creating another application force to move said metering piston downwardly and actuate the inlet valve element 67, as previously described; however, since the effective area A of the relay piston 60 in the outlet chamber 71 is greater than the area A thereof in said application chamber, the magnitude of the applied fluid pressure at the outlet port 5 7 acting on the area A is proportionally smaller than that of the established fluid pressure at the outlet port 31 acting on the area A Often the vehicle operator is required to effect emergency vehicle deceleration or a complete stop in order to avoid emergency conditions or situations, such as collisions with other vehicles and/or objects in the roadway, whenever such emergency conditions occur. It is the natural tendency or reaction of vehicle operators to further actuate or effect complete actuation of the control valve when these emergency conditions arise; therefore, it is mandatory to have full tank pressure available for dumping at both the outlet ports 31, 57 of the control valve 3 in order to utilize the maximum effectiveness of the friction devices (not shown) available under such emergency operating conditions when the two-way valve 13 is positioned to condition the control valve 3 for a ratio braking application. In this vein, the link 74 is provided to mechanically override the ratio condition of the control valve 3. For instance, when the control valve 3 is actuated to effect a ratio breaking application, as previously described, the reaction piston 44 is further movable in response to the applied force upon the occurrence of an emergency condition to further actuate the inlet valve element 37 toward its wide open or dumping position and drivingly engage the link 74. Upon this driving engagement, the link 74 defines a mechanical connection between the reaction and metering pistons 44, 60 which are thereafter concertedly movable in response to the applied force to mechanically actuate the valve element 67 toward its wide open or dumping position. In View of the foregoing, it is apparent that the metering piston 60 is driven by the reaction piston 44 and link 74 to mechanically actuate the valve element 67 in order to override the pre-selected ratio braking condition of the control valve and dump full tank pressure at each of the outlet ports 31, 57; therefore, the maximum fluid pressure available in the system 1 is provided to effect the maximum energization of the friction devices available under emergency operating conditions when the control valve 3 is conditioned for a ratio braking application.

From the foregoing, it is now apparent that a novel control valve is provided meeting the objects and advantages set out hereinbefore, as well as other objects and advantages, and that changes or modifications as to the precise configuration, shapes and details of the constructions set forth in the disclosure by way of illustration may be made by those skilled in the art Without departing from the spirit of the invention, as defined by the claims which follow.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A control valve for a fluid pressure system having a pair of fluid pressure responsive motors and a fluid pressure source comprising a housing, a pair of application means movable in said housing, means within said housing including one of said application means defining a pressure fluid flow passage for connection between said source and one of said motors, other means within said housing including the other of said application means defining another pressure fluid flow passage having one end for connection with the other of said motors and the other end thereof connected with said first named flow passage, said one application means being movable in response to an applied force to a position in said first named flow passage establishing pressure fluid flow there through, the other of said application means being movable in response to the established fluid pressure in said first named flow passage to a position in said other flow passage effecting the application of the established fluid pressure therethrough, and opposed areas on said other application means respectively responsive to the established and applied fluid pressure in said other flow passage to predetermine the ratio there'between.

2. The control valve according to claim 1, wherein one of said opposed areas is greater than the other of said opposed areas and the magnitude of the applied fluid pressure acting on one of said one and other areas is proportionally less than the magnitude of the established fluid pressure acting on the other of said one and other areas.

3. The control valve according to claim 1, wherein said other application means also defines with said housing an expansible fluid pressure chamber for selective connection with the atmosphere and with the established fluid pressure in said first named flow passage, and a ratio area on said other application means for subjection to fluid pressure in said chamber and additive to one of said opposed areas wherein the established and applied fluid pressures are in a predetermined ratio when said chamher is connected with the atmosphere and in a ratio different from the predetermined ratio when said chamber is connected with the established fluid pressure in said first named flow passage.

4. The control valve according to claim 1, wherein said other application means also defines with said housing an expansible fluid pressure chamber for selective connection with the atmosphere and with the applied fluid pressure in said other flow passage, and a ratio area on said other application means for subjection to fluid pressure in said chamber and additive to one of said opposed areas, the magnitudes of the established and applied fluid pressures being in a predetermined ratio when said chamber is connected with the atmosphere, and said other application means being responsive to fluid pressure in said chamber acting on said ratio area when said chamber is connected with the applied fluid pressure in said other flow passage to further eflect the application of the established fluid pressure through said other flow passage until the magnitudes of the established and applied fluid pressures are substantially equal.

5. The control valve according to claim 1, comprising valve means in said first named flow passage controlling pressure fluid flow therethrough, said one application means being movable in response to the applied force to engage and actuate said valve means to effect the established fluid pressure in said first named flow passage, other valve means in said other application means controlling pressure fluid flow through said other flow passage, opposed ends on said other application means respectively defining said opposed areas responsive to the established and applied fluid pressure in saidother flow passage, said other application means being movable in response to the established fluid pressure acting on one of said opposed ends to actuate said other valve means and eflect the applied fluid pressure in said other flow passage, the applied fluid pressure acting on the other of said opposed ends to oppose further movement of said other application means and being in a predetermined ratio with the established fluid pressure.

6. The control valve according to claim 5, wherein said other flow passage includes a reaction chamber in said housing adjacent to said other opposed end for connection with said other motor, an application chamber in said housing adjacent to said one opposed end, passage means connected between said application chamber and said first named flow passage, and a connecting passage in said other application means between said application and reaction chambers, said other valve means being movable in said connecting passage.

7. The control valve according to claim 5, comprising a valve seat on said other application means in circumscribing relation with said other flow passage, said other valve means being normally urged into engagement with said valve seat closing said other flow passage, and another valve seat on said housing, said other application means being initially movable in response to the established fluid pressure to engage said other valve means with said other valve seat and being thereafter further movable relative to said other valve means to a position disengaging said first named valve seat from said other valve means and opening said other flow passage.

8. The control valve according to claim 7, comprising an exhaust passage in said housing extending through said other valve seat for venting said other motor to the atmosphere, said exhaust passage being closed upon the engagement of said other valve means with said other valve seat.

9. The control valve according to claim 6, wherein a portion of said one end of said other application means also defines with said housing a control chamber in opposed relation with said reaction chamber for selective connection in pressure fluid communication with the atrnosphere and with the established fluid pressure in said first named flow passage, and a control area on said portion of said one end for subjection to fluid pressure in said control chamber, said control area being additive to the opposed area on said one opposed end and opposed to the opposed area on the other opposed end wherein the applied and established fluid pressures in said first named and other flow passages are in the predetermined ratio when said control chamber is connected with the atmosphere and in another ratio different than the predetermined ratio when said control chamber is connected with the established fluid pressure in said first named flow passage.

It). A control valve comprising a housing having an inlet port and a pair of outlet ports therein, valve means controlling pressure fluid communication between said inlet port and one of said outlet ports, a pair of valve control members movable in said housing, one of said valve control members being movable in response to an applied force to engage and move said valve means to a position establishing pressure fluid communication between said inlet port and said one outlet port, the other of said valve control members defining with said housing and expansible fluid pressure chamber, means in said housing providing passage of the established fluid pressure at said one outlet port into said chamber, other valve means in said other valve control member controlling pressure fluid communication between said outlet ports, said other valve control member being movable in response to the established fluid pressure at said one outlet port to move .said other valve means to a position establishing pressure fluid communication between said outlet ports and a pair of opposed areas on said other valve control member respectively responsive to the established fluid pressures at said one and other outlet ports to predetermine the ratio therebetween.

11. The control valve according to claim 10, wherein one of said opposed areas is greater than the other of said opposed areas and the magnitude of the established fluid pressure at said other outlet port acting on one of said one and other opposed areas is proportionally less than the magnitude of the established fluid pressure at said one'outlet port acting on the other of said one and other opposed areas.

12. The control valve according to claim 10, comprising a third area on said other valve control member in opposed relation to one of said pair of opposed areas for selective subjection to the established fluid pressure at one of said one and other outlet ports and the atmosphere, the established fluid pressures at said outlet ports being in the predetermined ratio when said third area is subjected to the atmosphere and being in another ratio diflerent than the predetermined ratio when said third area is subjected to the established fluid pressure at said one of said one and other outlet ports.

13. The control valve according to claim 10', comprising a valve seat on said other valve control member, a connecting passage in said other valve control member extending through said valve seat between said chamber and said other outlet port, said other valve means being normally urged into engagement with said valve seat closing said connecting passage, another valve seat on said housing, exhaust passage means in said housing extending through said other valve seat normally venting said other outlet port to the atmosphere, said other valve control member being initially movable in response to the established fluid pressure at said one outlet port to engage said other valve means with said other valve seat closing said exhaust passage means and thereafter further movable relative to said valve means to a position disengaging said first named valve seat from said other valve means and opening said connecting passage.

14. The control valve according to claim 10, comprising a mechanical connection between said valve control members, said mechanical connection being responsive to the applied force movement of said one valve control member to mechanically drive said other valve control member and actuate said other valve means.

References Cited UNITED STATES PATENTS 3,227,495 1/1966 Bueler 303-52 EUGENE G. BOTZ, Primary Examiner. 

1. A CONTROL VALVE FOR A FLUID PRESSURE SYSTEM HAVING A PAIR OF FLUID PRESSURE RESPONSIVE MOTORS AND A FLUID PRESSURE SOURCE COMPRISING A HOUSING, A PAIR OF APPLICATION MEANS MOVABLE IN SAID HOUSING, MEANS WITHIN SAID HOUSING INCLUDING ONE OF SAID APPLICATION MEANS DEFINING A PRESSURE FLUID FLOW PASSAGE FOR CONNECTION BETWEEN SAID SOURCE AND ONE OF SAID MOTORS, OTHER MEANS WITHIN SAID HOUSING INCLUDING THE OTHER OF SAID APPLICATION MEANS DEFINING ANOTHER PRESSURE FLUID FLOW PASSAGE HAVING ONE END FOR CONNECTION WITH THE OTHER OF SAID MOTORS AND THE OTHER END THEREOF CONNECTED WITH SAID FIRST NAMED FLOW PASSAGE, SAID ONE APPLICATION MEANS BEING MOVABLE IN RESPONSE TO AN APPLIED FORCE TO A POSITION IN SAID FIRST NAMED FLOW PASSAGE ESTABLISHING PRESSURE FLUID FLOW THERETHROUGH, THE OTHER OF SAID APPLICATION MEANS BEING MOVABLE IN RESPONSE TO THE ESTABLISHED FLUID PRESSURE IN SAID FIRST NAMED FLOW PASSAGE TO A POSITION IN SAID OTHER FLOW PASSAGE EFFECTING THE APPLICATION OF THE ESTABLISHED FLUID PRESSURE THERETHROUGH, AND OPPOSED AREAS ON SAID OTHER APPLICATION MEANS RESPECTIVELY RESPONSIVE TO THE ESTABLISHED AND APPLIED FLUID PRESSURE IN SAID OTHER FLOW PASSAGE TO PREDETERMINE THE RATIO THEREBETWEEN. 